1970 carrier bearing info

[joe70]

I have went through as many threads i can find on my truck,it is a chevy 1/2 ton with leaf spings.The PO rebuilt drive shaft.When I went through u joints and measured them they seem correct,also the horse shoe support bearing looks ok{I did not take apert and mic it}.My questin is should I have horse shoe or clamshell surrport bearing.I 'am asking because I can feel a little vibration,and do not how many miles are on the rebuilt drive shaft or if the PO had balanced it after rebuilding it.Also the phasing is correct.Any info would be welcome.

Joe